loop0: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.311/6770 is trying to acquire lock: ffff888054a000f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xa1/0xb10 fs/hfs/extent.c:397 but task is already holding lock: ffff8880309760b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x1c3/0x240 fs/hfs/bfind.c:36 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&tree->tree_lock#2/1){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760 hfs_find_init+0x1c3/0x240 fs/hfs/bfind.c:36 hfs_ext_read_extent+0x19b/0x9e0 fs/hfs/extent.c:200 hfs_get_block+0x55f/0x830 fs/hfs/extent.c:366 block_read_full_folio+0x457/0x850 fs/buffer.c:2420 filemap_read_folio+0xc8/0x2a0 mm/filemap.c:2413 do_read_cache_folio+0x263/0x5c0 mm/filemap.c:3957 do_read_cache_page mm/filemap.c:4023 [inline] read_cache_page+0x5b/0x160 mm/filemap.c:4032 read_mapping_page include/linux/pagemap.h:985 [inline] __hfs_bnode_create+0x62d/0x8a0 fs/hfsplus/bnode.c:538 hfs_bnode_find+0x2dc/0xd50 fs/hfs/bnode.c:433 hfs_brec_find+0x2b1/0x540 fs/hfs/bfind.c:129 hfs_brec_read+0x26/0x120 fs/hfs/bfind.c:168 hfs_cat_find_brec+0xd8/0x2c0 fs/hfs/catalog.c:194 hfs_fill_super+0x47f/0x730 fs/hfs/super.c:350 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1692 vfs_get_tree+0x8e/0x340 fs/super.c:1815 do_new_mount fs/namespace.c:3808 [inline] path_mount+0x1513/0x2000 fs/namespace.c:4123 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount fs/namespace.c:4324 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760 hfs_extend_file+0xa1/0xb10 fs/hfs/extent.c:397 hfs_bmap_reserve+0x2a2/0x390 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x3cf/0x520 fs/hfs/extent.c:121 hfs_ext_write_extent+0x1b5/0x1f0 fs/hfs/extent.c:144 hfs_write_inode+0xc3/0x9f0 fs/hfs/inode.c:429 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0xb3e/0xfb0 fs/fs-writeback.c:1745 writeback_single_inode+0x2bc/0x550 fs/fs-writeback.c:1801 write_inode_now+0x170/0x1e0 fs/fs-writeback.c:2864 hfs_file_fsync+0xa7/0x190 fs/hfs/inode.c:676 vfs_fsync_range+0x139/0x220 fs/sync.c:187 generic_write_sync include/linux/fs.h:3043 [inline] generic_file_write_iter+0x305/0x3c0 mm/filemap.c:4322 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x7d3/0x11d0 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tree->tree_lock#2/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock#2/1); lock(&HFS_I(tree->inode)->extents_lock); *** DEADLOCK *** 4 locks held by syz.0.311/6770: #0: ffff88804d0ad978 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1232 #1: ffff888030974428 (sb_writers#26){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #2: ffff888054a01620 (&sb->s_type->i_mutex_key#32){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #2: ffff888054a01620 (&sb->s_type->i_mutex_key#32){+.+.}-{4:4}, at: hfs_file_fsync+0x9d/0x190 fs/hfs/inode.c:673 #3: ffff8880309760b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x1c3/0x240 fs/hfs/bfind.c:36 stack backtrace: CPU: 0 UID: 0 PID: 6770 Comm: syz.0.311 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2043 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760 hfs_extend_file+0xa1/0xb10 fs/hfs/extent.c:397 hfs_bmap_reserve+0x2a2/0x390 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x3cf/0x520 fs/hfs/extent.c:121 hfs_ext_write_extent+0x1b5/0x1f0 fs/hfs/extent.c:144 hfs_write_inode+0xc3/0x9f0 fs/hfs/inode.c:429 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0xb3e/0xfb0 fs/fs-writeback.c:1745 writeback_single_inode+0x2bc/0x550 fs/fs-writeback.c:1801 write_inode_now+0x170/0x1e0 fs/fs-writeback.c:2864 hfs_file_fsync+0xa7/0x190 fs/hfs/inode.c:676 vfs_fsync_range+0x139/0x220 fs/sync.c:187 generic_write_sync include/linux/fs.h:3043 [inline] generic_file_write_iter+0x305/0x3c0 mm/filemap.c:4322 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x7d3/0x11d0 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7645f8eba9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7646eba038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f76461d5fa0 RCX: 00007f7645f8eba9 RDX: 0000000000000c34 RSI: 0000200000000940 RDI: 0000000000000004 RBP: 00007f7646011e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f76461d6038 R14: 00007f76461d5fa0 R15: 00007ffe4e68e548